Unilateral: (of an action or decision) performed by or affecting only one person, group, or country involved in a particular situation, without the agreement of another or the others.Get Off My Lawn said:
You can get to vaccination requirements in a round-about way, but yes, I fully expect a CYA clause. My point is simply that the understood landscape of service was changed unilaterally, and as Americans we wouldn't accept "well, you signed so you gave up your right to bodily autonomy" in any other domain.
Grandfather Clauses are commonplace in the military for the reason that servicemen still have rights and others don't get to change their terms mid-flight.
While the decision to add the covid vaccine can be seen as a unilateral decision this is, in many ways, simply how a military organization has to operate. Soldiers, enlisted and officers alike, more often than not have zero say in what they do and how they do it. Decisions, by the nature of the military, is forced upon them. Soldiers don't get a vote.